1. Field of the Invention
The present invention relates to an image communication apparatus and, more particularly, to an image communication apparatus, method, and system which have an external I/F (INTERFACE) unit which can be connected to an information processing terminal.
2. Related Background Art
In some image communication apparatuses which are connected to information processing terminals such as personal computers and can be controlled by commands from the information processing terminals, the reading, recording, and communication functions as the main functions of the image communication apparatuses can be started from the information processing terminal side. As an interface for this operation, the RS232C interface, which is mounted in most of the information processing terminals, has been generally used.
Such a conventional image communication apparatus has both a buffer for temporarily storing image data transmitted/received through a telephone line, and a buffer for temporarily storing data to be transferred to/from an information processing terminal.
In this conventional image communication apparatus, a document read mode cannot be easily set by an instruction from an information processing terminal.
Even if an error occurs while document data is stored in a memory in accordance with an instruction from the information processing terminal, the image data is left in the memory.
This conventional image communication apparatus has no means for directly transmitting data of a document on a reading means in accordance with an instruction from the information processing terminal or cannot easily set the read mode for a send document in accordance with an instruction from the information processing terminal.
The image communication apparatus can select either a mode of temporarily storing received image data in the memory, outputting the data to the printer unit, and deleting the data from the memory upon completion of a recording operation in the printer unit, or a mode of storing all received image data in the memory without recording the data with the printer unit.
The image communication apparatus which can be connected to the information processing terminal simply outputs communication control information associated with transmission/reception results to the information processing terminal in accordance with an instruction from the information processing terminal.
As an interface for connection with the information processing terminal, an interface for full-duplex communication, which is always capable of bidirectional data transfer, has been used. For this reason, if it is determined that processing based on an instruction from the information processing terminal can be executed, the image communication apparatus outputs the corresponding information to the information processing terminal, and immediately executes the processing.
In the above prior art, the RS232C interface is a low-speed interface used to perform full-duplex communication by a serial transfer scheme. With the recent remarkable increase in the processing speed of an information processing terminal and an image communication apparatus, data transfer of higher speeds is required. Under the circumstances, there is a movement toward standardization of parallel interfaces mounted in many information processing terminals as interfaces capable of two-way communication instead of conventional one-way communication. This is a standard called IEEE P1284. With the use of this interface, data transfer based on high-speed two-way communication can be realized. However, the parallel interface defined by IEEE P1284 can only perform half-duplex communication. Even if, therefore, data to be transferred to the information processing terminal is present in the image communication apparatus, the data cannot be transferred sometimes. In such a case, until data transfer is completed, any other instructions cannot be received.
In addition, in the conventional image communication apparatus, a buffer for temporarily storing image data transmitted/received through a telephone line, and a buffer for temporarily storing data to be transferred to/from the information processing terminal must be separately ensured in a RAM.
A document read mode cannot be easily set for each page, and the apparatus settings change every time a read mode is set.
In the conventional communication apparatus, even if an error occurs while document data is being stored in the memory in accordance with an instruction from the information processing terminal, the image data is left in the memory.
In order to allow the apparatus in any state to receive and execute a document read instruction from an external information processing terminal, complicated control is required, resulting in an increase in cost.
In order to allow the apparatus to instruct an operation or change the settings through the operation panel while the apparatus is executing a document read instruction received from an external information processing terminal, complicated control is required, resulting in an increase in cost.
A read mode for document data to be transmitted cannot be easily set.
In addition, in the above conventional image communication apparatus, when all received image are stored in the memory without recording the data with the printer unit, the contents of the image data cannot be checked without transferring all the image data to the information processing terminal or without recording all the image data by using the operation panel. That is, the operator must perform a cumbersome operation.
In addition, the above receive mode cannot be set from the information processing terminal, so the operator must go to the image communication apparatus to set the mode by using the operation panel.
In the above conventional image communication apparatus, communication control information is simply output to the information processing terminal. For this reason, in order to check the reception result, the operator must separate the necessary reception result from the communication control information. Furthermore, since communication control information associated with transmission/reception results is simply output to the information processing terminal, the operator cannot know, using the information processing terminal, that data is being received. In addition, since information associated with a reception result which was output to the information processing terminal is notified again, the operator must compare the currently notified information with the information notified in the past to determine which is the latest information.
The above parallel interface defined by IEEE P1284 can only perform half-duplex communication. Even if, therefore, data to be transferred to the information processing terminal is present in the image communication apparatus, the data may not be transferred. For this reason, if the image communication apparatus is designed to notify information indicating the execution of an operation designated by the information processing terminal thereto upon completion of the operation, information indicating the execution of a designated operation may not be notified to the information processing terminal in spite of the fact that the operation is actually executed. In this case, since the image communication apparatus executes a designated operation even though the information processing terminal does not recognize whether the image communication apparatus executes the operation, synchronization cannot be established between the information processing terminal and the image communication apparatus. A problem is therefore posed in terms of reliability.
Assume that the image communication apparatus is designed to execute an operation designated by the information processing terminal after notifying the information processing terminal that the operation can be executed. In this case, the image communication apparatus cannot execute the operation until notification to the information processing terminal is completed. Even an urgent operation cannot be executed immediately. Furthermore, since an execution result, e.g., the execution result of an operation interrupt instruction, which should be notified to the information processing terminal cannot be notified, the information processing terminal cannot determine whether the image communication apparatus has actually executed the interrupt operation. A problem is therefore posed in terms of reliability.